Objectives: To examine the relationship between EEG attributes and clinic attacks, and to define the value of inter-ictal EEG observation in defining the prognosis.

Materials and Methods: Seventy four patients registered at PTT Training Hospital Neurology Clinic Epilepsy unit and 387 EEG belonging to them were evaluated retrospectively and prospectively. An EEG examination was accepted abnormal if it included epileptiform activity, slow wave, amplitude anomalies, or if resembled normal activity but displayed certain patterns indicating deviations in frequency, reactivity, dispersion and in other attributes. A decrease of more than 50% in normal or inter-ictal epileptiform activities, or in above mentioned EEG abnormalities was accepted as an improvement in EEG pattern. Ability to control clinically defined attacks (no attacks experienced by the patient) or a decrease of more than 75% compared to the period before the initiation of medication are accepted as indicators of good prognosis.

Results: Our study group comprised 36(48.6%) female and 38(51.4%) male patients, with a mean age of 21.62±12.72 (R:9–78). Of 26 subjects with good prognosis, betterments were observed during EEG examinations in inter-ictal activities in 16(%44.4). Twenty (55.6%) subjects among 48 patients with bad prognosis were observed to have betterments in inter-ictal activities. Relations between EEG findings and prognosis were evaluated via chi-square tests. There was no statistically significant difference between percentage rates (P=0.103).

Conclusion: Inter-ictal EEG attributes may give information about the prognosis and the presence of clinic attacks. The analysis is more valuable in adult patients without any associated pathology. It was suggested that studies with a greater number of patients examining a greater number of EEGs is required. ©2006, Fırat Üniversitesi, Tıp Fakültesi